Mozilla Monitor website will be down for 2 hours starting 5/20/2025 at 6 AM PT. Visit our status site for updates.

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Why has my Thunderbird screen shrunk?

Everything has reduced in size making it harder to read.

Everything has reduced in size making it harder to read.

Chosen solution

Hi Zenos. It works and has re-sized back to normal. Thanks very much.

Read this answer in context 👍 0

All Replies (9)

The simplest way to adjust the size of text in Thunderbird's menus and message lists is to use this add-on:

https://addons.mozilla.org/en-us/thunderbird/addon/theme-font-size-changer/

Modified by Zenos

Top Menu -> View -> Zoom -> Reset

Zenos said

The simplest way to adjust the size of text in Thunderbird's menus and message lists is to use this add-on: https://addons.mozilla.org/en-us/thunderbird/addon/theme-font-size-changer/

I have done this but the add-on doesn't appear on any menu.

Beerbaron23 said

Top Menu -> View -> Zoom -> Reset

Done that. No change. Do I need to re-start?

Did you install the add-on?

It appears at the foot of the Tools menu drop-down here in Windows.

BeerBaron's advice applies to message content. My advice was aimed at menus, message lists etc. I'm still not sure which of these applies to your situation.

If it's message text that's too small, and you need something other than 100% zoom level, please say. I think there are better ways than fiddling with zoom.

Modified by Zenos

Thanks Zenos. It now tells me the add-on is installed. But I can't find it on any menu, nor as an icon on the tools bar. This seems to be above my computing pay grade (which isn't very high). I have tried re-starting Thunderbird and re-booting the computer.

It has options to hide/show it in the main menu or in the Application Menu (button with three bars). Regardless of these settings, I can't actually find it in the Application Menu.

So you may need to look in the old-fashioned menu, across the top. If you don't have one, use F10 or alt, then View|Tools.

I also have it as a toolbar button. To get this you may have to customize your main toolbar.

https://support.mozilla.org/en-US/kb/how-customize-toolbars

Modified by Zenos

Zenos said

It has options to hide/show it in the main menu or in the Application Menu (button with three bars). Regardless of these settings, I can't actually find it in the Application Menu. So you may need to look in the old-fashioned menu, across the top. If you don't have one, use F10 or alt, then View|Tools. I also have it as a toolbar button. To get this you may have to customize your main toolbar. https://support.mozilla.org/en-US/kb/how-customize-toolbars

Chosen Solution

Hi Zenos. It works and has re-sized back to normal. Thanks very much.